1. Field of the Invention
The present invention relates to a method of mounting an optical sensor package in which an optical sensor package such as a charge coupled device (CCD) or the like used, for example as a distance measuring device for an automatic focusing device for a camera, can be accurately mounted on a mounting member.
2. Related Background Art
A current optical sensor has been used in various apparatuses. For example, a subject distance is measured with an optical sensor even in an autofocusing apparatus for a camera. After the optical sensor which is used therein is formed on a chip, it is generally sealed with resin or the like to be packaged.
FIG. 6 shows a structure of such optical sensor package 55. As shown in FIG. 6, a chip 52 on which an optical sensor 51 is formed is wire-bonded to a lead frame 53 and the entire sensor package is sealed with resin 54. Further, the mounting method for the optical sensor package has been variously proposed.
FIG. 5 is a general optical sensor package disclosed in Japanese Laid-Open Patent Application No. 8-62491. As shown in FIG. 5, an optical sensor package 45 shown in FIG. 6, which is soldered to be mounted on a flexible printed-circuit board (hereinafter referred to as FPC) 49 is held on a holding member 48. That is, the resin 44 which seals the chip 42 is held on the holding member 48 and the holding member 48 is mounted on a base plate 46. A position control of the optical sensor 41 is performed by providing a tool (not shown) on the holding member 48 and handling this tool.
However, in the mounting method for the optical sensor package shown in FIG. 5, the resin which seals the chip 42 of the optical sensor package 45 is held on the holding member 48. Thus, there are the following disadvantages.
Since the optical sensor package 45 generally has a large error in the outer diameter, for example, the concave portion 48a of the holding member 48 should be designed in large scale so that the error can be absorbed by the holding member 48, resulting in a large holding member 48.
Further, the large error in the outer diameter of the package 45 causes even a position shift of the optical sensor 41 with respect to an image formation lens 47 mounted on the base plate 46. Accordingly, an amount of adjustment for the correction of the position shift must be increased and provision of a large space in a mounting portion for the optical sensor package 45 is needed. Therefore, a size of the whole package mounting portion is increased.
Further, this adjustment of the position shift is carried out by moving the holding member 48 holding the optical sensor package 45. Thus, the tool force can also act on the optical sensor package 45 as an undesirable stress, and the accuracy of the adjustment can be deteriorated.
On the other hand, recently, an optical sensor package 65 shown in FIG. 7 in which a part of a chip 62, on which an optical sensor package 65 is formed, is three-dimensionally exposed has been also proposed. Such optical sensor package 65 is formed such that the sensor surface is directly bonded to one side of an FPC 63 and a protective glass member 64 is connected to the other side of the FPC 63.
An object of the present invention is to solve the above-mentioned problems. Specifically, an object of the present invention is to provide a method of mounting an optical sensor package in which the optical sensor package can be accurately mounted on a mounting member.
Another object of the present invention is to provide a method of mounting an optical sensor package in which by using an optical sensor package having a chip on which an optical sensor was formed, a part of the chip being exposed, the exposed chip portion can be directly mounted on a mounting member.
Still another object of the present invention is to provide a method of mounting an optical sensor package in which the optical sensor package can be mounted by using an optical sensor package having a chip on which an optical sensor was formed, a part of the chip being exposed, forming a concave portion corresponding to the outer shape of the exposed chip portion in a mounting member, and fitting the exposed chip portion into the concave portion of the mounting member.
Still another object of the present invention is to provide a method of mounting an optical sensor package in which an exposed chip in the optical sensor package can be mounted on a mounting member through a holding member or a receiving member on the holding member.